1. Field of the Invention
The present invention relates to an optical element and an optical assembly, and more particularly to a directional light distributing optical element and a directional light distributing optical assembly.
2. Related Art
Due to the advantages of light, thin, and low power consumption, the Liquid Crystal Display (LCD) is widely applied to portable electronic devices such as a notebook computer, a mobile phone, and a Personal Digital Assistant (PDA). However, the liquid crystal does not have the characteristic of luminescence, so the LCD needs a light-emitting device to realize the display function.
Currently, the color filter of the LCD in the prior art adopts the manner of absorbing and generating red, green, blue lights, and this manner will cause the substantial decrease of the using rate of the energy. To solve the above problem, a new LCD architecture design technique is gradually popularized.
Generally speaking, when a divergence angle of an incident light of a light source (hereinafter referred to as a backlight source for short) of a backlight module is too large, the light of various colors cannot be accurately incident on the subpixel of the liquid crystal to generate a color mixture phenomenon of a cross-talk (that is, the picture on a certain region of the display influencing the brightness of the adjacent region), such that the color saturation of the light after passing the panel is greatly reduced. In addition to generating a uniform directional light, the backlight source must reach the 70%-80% uniformity of the light, so the light source is required to be kept approximately parallel in one dimension and dispersed in another dimension at 90° different from the one dimension.
Since the backlight source in the LCD has a high requirement for collimation, the packaging technique of the general Light-Emitting Diode (LED) cannot meet the collimation requirement of the backlight source.